Short for Serial Digital Interface. In general, carries uncompressed digital video, multiple audio tracks and other data over a 75-ohm coax cable with BNC connector. SDI SMPTE 259M, for SD 4:2:2 digital television, handles a 270 Mb/s transfer rate at distances of more than 200 meters. HD-SDI, standardized in SMPTE 292M, is for 4:2:2 HD television, at 1.485 Gb/s, using fiber optic cable for distances up to 2 km. 3G SDI under SMPTE 424M operates at 2.97 Gb/s, twice the HD-SDI clock rate, and is designed to carry high bandwidth HD television (e.g. 1080/50P and 1080/60P) and 2K DI images.
Canon glossary us